Digger tooth construction



April 21, 1953 M. D. HOSTET'IER 2,635,366

DIGGER TOOTH CONSTRUCTION Filed Jan. 24, 1947 2 SHEETS-SHEET 1 INVENTOR.

April 21, 1953 M. D. HOSTETTER 2,635,365

DIGGER TOOTH CONSTRUCTION Filed Jan. 24, 1947 2 SHEETS-SHEET 2 INVEN TOR.

Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE My invention relates to an improved. digger tooth construction of the character embodied in my application, Serial No. 665,149, filed April 26th, 1946, in which a socketed digging point is removably mounted on a tang of a supporting body carried by the digging bucket, the digging point being releasably locked on the tang to permit detachment thereof for resharpening or replacement, by a locking means embodying a resilient element, and a coacting rotatable key.

It is a purpose of my present invention to provide a digging point locking means which is functionally characterized by its ability to so look the point on the tang as to prevent is loosening or accidental release under any and all conditions of use, and particularly under any forward movement of the point on the tang resultant of back-slap produced as when striking a rock during retrograde movement of the tooth.

Another purpose of my invention is the provision of a point locking means further characterized by a structural organizationwhich, should the resilient element fail to function because of breakage thereof, the point will remain locked on the tang, and yet, when required, the locking means can still be actuated as before to release the point.

A further purpose of my invention is the provision of digger tooth construction in which the point-locking means includes a spring for urging the digger point rearwardly on the digger tang, and where the construction ofthe point and tang is such that earth can enter between certain parts of the locking means to coact therewith in forming a solid body between the point and tang which effectively resists, independently of the spring, any backslap exerted on the point as when striking a rock during retrograde movement of the tooth, and thus protecting the spring against distortion as would otherwise occur, so that the spring will function as intended at all times. Also, the construction of the point and tang is such that earth entering the two, which would otherwise interfere with manual release of the locking means, can be easily removed.

I will described only one form of digger tooth construction embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings:

Fig. 1 is a view showing in perspective one form of digger tooth construction embodying my invention, and in applied position on the edge of a digger bucket.

Fig. 2 is an enlarged longitudinal vertical sectional view of the digger tooth construction boss 38 on the digging point.

5 Claims. (Cl. 37-142) shown in Fig. 1, and with the digging point in locked position on the tang.

Fig. 8 is a horizontal sectional view taken on the lines 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2 and showing the digging point in the process of being applied to the tang.

Fig. 5 is a fragmentary top plan view of Fig. 4.

Fig. 6 is a view similar to Fig. 5 but with the point pushed further rearwardly on the tang, and the locking cam in position preliminarily to its movement to locking position.

Fig. 7 is a vertical sectional view taken on the line 7-1 of Fig. 3.

Having specific reference to the drawings, my invention in its present embodiment comprises a supporting body 15 (see Fig. 1) having a rearwardly open socket l6 receiving a supporting base i! suitably fixed to and projecting forwardly from the forward edge It of a digger bucket.

The body l5 includes an integral and forwardly extending tang It also tapered and bordered at its top by a transverse shoulder 26 and at its sides by vertical extending shoulders 2|. Ahead of the top shoulder 20 and in the upper face of the tang I9 is a groove 22 extending along the major aXis of the tang and communicating at its forward end with a pocket 23. This pocket is of the same depth as the groove, and at one side it is widened and rounded by a curved wall 24. A straight end wall 25 connects the curved side wall 24 with the other side wall 26, and the latter wall is a straight continuation of one side wall of the groove 22.

Extending upwardly from the bottom or inclined face of the tang I 9 and communicating with the pocket 23 is an opening 2! circular in cross section and providing a bearing for a stub shaft 28 which extends into the pocket where it is provided with a crank 29. This crank seats on the bottom wall of the pocket 23 and its free end provides a cam having a rounded portion 36 and a flat portion 3|. On the upper side of the crank 29 and coaxially with the stub shaft 28 is fixed a head 32 which, in the present instance, is 7 provided with a socket 33 for the reception of a suitable wrench by which the crank can be turned, as will be more fully described hereinafter.

The crank 29 constitutes part of the means for looking a digging point 34 on the tang E9, the remainder of such locking means including a resilient element 35, which may be in the form of a spiral spring, two plugs 36 and 3?, and a v H N The plugstfi and 31, the spring 35, and the boss 38, are all received within the groove 22, the plugs and the spring being interposed between the crank 29 and the boss 38, and the spring confined on the plugs by annular flanges 39 on the outer ends of the plugs.

By means of an upper wall which is an extension of the point 34, a lower wall 4| welded to the upper wall and divergent thereto, and side Walls 41a, an upwardly tapering and rearwardly opening socket 421 is provided in which the tang. I9 is adapted to be-recei'ved. The wall 40 is provided with an opening 43 of such size and shape that the crank 29 and its stub shaft 28 can be extended downwardly through thewall and into the pocket 23 and the bearing 21. In this position of the crank the head 32 is so-located within.

the opening 43 as to allow the application of a.

wrench thereto for rotating the crank.

Because the crank 29 is adapted to be. applied through the opening 43, once it is applied and turned to locking position, a portion of the pocket 23 is exposed to the opening, and, hence, earth is apt to enter the pocket during use of the digging tooth. There may be such an accumulation of earth within the pocket as to prevent rotation of the crank from locking to releasing position, in which event release of the digging point from the tang-could not be effected.

To avoid this difliculty, thebottom of the pocket 23 is provided with an opening" 44 (see Figures, 3 and 7) which: is in registration with an outer. opening in the. bottom wall 4| of the digging point when the point. is properly seated on the tang. The upper opening 44 is accessible through the opening 43 to allow asuitableinstrument to be extended into the pocket and. manipulated to loosen the earth therein. and to. force it downwardly through the opening 44- and outwardly through the opening 45.

In order to mount the digging point 34 on the tang [9, the spring 35 and the. plugs 35 and 3.1 are first placed within the groove 22, whereupon the point can be movedrearwardly to extend the tang into the socket. During this movement. the boss 38- passes rearwardly and downwardly into the groove 22 adjacent the rear end thereof clearing the spring 35 and plugs. 36 and 31.. To insure this the spring and plugs as applied are positioned adjacent the forward end of the groove with the front plug 38 extending. into the pocket 23.

After they digging point has been properly seated onv the. tang as illustrated in Figs. 2 and 6, the plugs and spring. may bev pushed rearwardly in the. groove by the use of. a suitable instrument, in order to allow the introduction of the crank 29 downwardly through the opening." and into the pocket 23,. with the stub shaft 28 rotatably fitted in the bearing 21. To efi'ect locking. of. the digging pointonthe tang, the. crank 29 is now rotated from the. extreme position shown in Fig. 6 to the extreme position shown. in Fig. 3, through application and manipulation of. a. wrench to the. head 32, as will be, understood.

Under such turning movementof. thecrank the. rounded cam portion 30 is brought into engagement with the confronting face of the forward plug 36 to force this plug rearwardly. The rear plug 31 being in engagement with the boss 38 resists this rearward movement of the forwardplug, to place the spring 35 under compression. By such loading of the spring aforce is now constantly exerted on the rear plug 31 which acts through the boss 38 to hold the digging point snugly fitted on the tang.

In the final position of the crank 23 the rounded cam portion 30 is past the center of the inner plug 36 to bring the flat portion 3| into engagement with the plug and to thus provide a broad seat for the crank against the plug which eliminates the possibility of the crank creeping backwardly and out of engagement with the plug and the consequent accidental release of the point from the tang. Thus the point is now securely locked on the tang and will remain so under all conditions of use. Should the spring 35 break it will allow the confronting ends of the plugs 36 and 3'! to move into contact with each other, and in so doing they would form a solid body between the boss38 and the crank 29 to prevent detachment of the digging point.

In theuse of digger teeth with detachable digging points, there is always the tendency of the point to be pulled forwardly on the tang as the toothis; withdrawn from earth formations, because of the incidental drag created on the point. If the digging point is not securely locked to the tang the aforedescribed pulling, of the point so loosens it on the tang that it is. free to rock on the tang. This motion exerts such strains and. stresses on the digging point particularly at the junction of the walls 4! and 40 as to soon break and. cause the point to become detached. from the tang. With the locking, means constructed in accordance with my invention, no movement or play can occur between the digging tooth and the tang such. as. to permit. of. the aforedescribed rocking movement, because any tendency of the digging point to move forwardly on the tang is effectively resisted by the plugs 36. and 31 being, brought into contact with each other.

Also, the earth entering the pocket 23 ultimately passes around the, crank 29 and between the confronting ends of the plugs. 36 and 31 to bridge the gap between. the plugs. and with the plugs. forming a continuous solid body between the boss 38 and the crank 29. By virtue of this solid body as so formed any forward force exerted on the digger point tending to pull the: point off of the tang, as when it strikes a rock. in its rearward and downward. movement of. the.

bucket of which the tooth forms a part, is not imposed on the spring 35 but on the solid body,

and thus the tension and set of the spring is preserved to at all times maintain the point snugly fitted on the tang.

To release. the digging point so that it canbe removed from the tang, it is. only necessary to, rotate the. crank 23 back toits original position, whereupon the forward plug 36 is free to advance in the groove 22 to relieve the spring 35 ofany, tension, and thereby permit forward movement of the boss 38v to allow complete removal of the.

digging point.

Although I have. herein shown and described only one form of digger tooth construction embodying my invention, it. is to be understood that:

ing in its top; and a head fixed on said crank andv projecting into said opening so as to. beaccessible by a wrench to rotate said crank.

2. A digger tooth construction, including: a tang, having'a pocket therein; a digging point removably mounted on said tang, and having an opening in the top thereof; and means releasably locking said point on said tang, comprising a crank insertable into said tang pocket through said opening and rotatable in said pocket; and a head fixed on said crank and projecting into said opening when the crank is within said pocket. so as to be accessible by a wrench for rotating the crank.

3. A digger tooth construction as embodied in claim 2, wherein the bottom of said pocket and the bottom of said point are formed with registering openings to permit expulsion from said pocket of earth accumulating therein.

4. A digger tooth construction, including: a tang having a pocket therein opening to the top thereof, and a groove communicating with and extending rearwardly from said pocket; 3, point having a socket receiving said tang, and an opening in the top communicating with said pocket; 8. boss on said point movable in said groove; a crank rotatable in said pocket; a pair of plugs in said groove between said boss and said crank, and normally spaced one from the other; a sprin between said crank and boss; and means accessible through said point opening for rotating said crank to load said spring, said pocket afiording a passage from said point opening to said groove through which earth may pass to and 6 between said plugs to bridge the gap therebetween and thus coact with the plugs to form a solid body between the crank and the boss to resist forward movement of the point on the tang independently of said spring.

5. A digger tooth construction, including: a tang; a digging point; and means for releasably locking said point on said tang, comprising spaced elements on said point and tang, a pair of members between said elements, a compression spring engaging said members for urging them apart, but allowing them to contact with each other in event of breakage of the spring, to form a solid body, and a crank between that element on said tang and one of said members for placing said spring under compression, the upper wall of the digging point provided with an opening through which said crank can be introduced between that element on the tang and one of said members, and that element on said point extending across and below the center of that member which it engages.

MORGAN D. HOSTETTER.

References Cited in the file of this patent UNITED STATES PATENTS Number 

